When a conventional centrifugal compressor is started, it is often necessary to totally close guide blades so as to prevent a starting current from being over-high. Meanwhile, a flow channel of an impeller outlet diffuser is narrowed. As a motor runs gradually and steadily, the guide blades are opened step by step, and it is necessary to slowly increase the width of the flow channel of the impeller outlet diffuser to a designed width.
In order to achieve a structural mode of this variable-section diffuser, several materials such as cams, guide rods and springs are often added to a position underneath a guide blade shaft, such that the guide blade shaft is pushed by the cams and the guide rods in an operating process, and the guide rods move backwards as needed under the counteraction of the springs. Thus, an adjustable diffuser can be driven to move forwards and backwards.
However, since synchronization of the cams driven by the guide blade shaft in the operating process cannot be completely guaranteed, synchronization of contact positions of the cams and the guide rods cannot be completely guaranteed, so that error accumulation is caused, it is quite easily caused that some of the guide rods are moving while the rest do not start to move yet, and the problem that the adjustable diffuser easily inclines and is stuck is caused by such non-synchronization, thereby causing serious consequences of cooling quantity insufficiency, surging or even damage to core parts such as an impeller and a bearing, and seriously threatening the reliability of the centrifugal compressor.